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Dec. 11, 1928. 7 1,694,501

} L. s. CHADWICK AUTOMATICALLY CONTROLLED BURNER Filed 00 6. s, 1925 9Sheets-Sheet 1 1,694,501 L. S. CHADWICK AUTOMATICALLY CONTROLLED BURNERFiled Oct. 5, 1925 9 ShGOtS-SIIOQt 2 full.

N i: am Am L. S. CHADWICK AUTOMATICALLY CONTROLLED BURNER Filed Oct. 5,1925 9 Sheets-Shut 4 L. S. CHADW|C K AUTOMATICALLY CONTROLLEP BURKEFiled Oct. 5, 1925 9 Sheets-Sheet 5 IIIII/l/II II/I/I/Il/I/I/II/II/l/Il/III I I Inventor W W ,2 @MMM Dec. 11, 1928. L. s. CHADWICK AUTOMATICALLYCONTROLLED BURNER 9 Sheets-Sheet 6 \\\\\\\\\\\\\\\\\\w\\\\\E\\\\\N\\\\\y N J Filed Oct. 5, 1925 ikmk JWMW R k g L. S. CHADWICK AUTQMATICALLYCONTROLLED "BURNER Dec. 1 1, I928.

Filed Oct. 5, 1925 9 Sheets-Sheet 7 Dec. 11, 1928.

L. S. CHADWICK AUTOMATICALLY CONTROLLED BURNER Filed Oct. 5, 1925 9Sheets-Sheet 8 Jim Dec. 11, 1928.

L. s. CHADWICK Filed Oct. 5, 1925 AUTOMATICALLY CONTROLLED BURNERPatented Dec. 11, 1928.

UNITED STATES PATENT OFFICE.

LEE S. CHADWICK, OF SHAKER HEIGHTS, OHIO, ASSIGNOR TO PERFECTION STOVECOMPANY, OF CLEVELAND", OHIO, A CORPORATION OF OHIO.

AUTOMATICALLY-CONTROLLED BURNER.

Application filed October 5, 1925. Serial No. 60,425.

This invention relates to automatically controlled fuel. oil'burningapparatus, and its primary purpose is to provide apparatus of thisnature that is highly eliicient, is thor- 5 oughly reliable, has a widetemperature range, and that may be easily and quickly adjusted tomaintain different desired temperatures of limited range.

Apparatus quite similar to that herein disclosed are exhibited inapplications Serial Nos. 726.657 and 30,999, filed jointly by MarcResek, J. Alger Dahlstrom and myself, on July 18, 1924 and on May 18,1925,1espectively, and more particularly in an-application filed by MarcResck, on April 18, 1925, and

bearing Serial No. 24,052.

The apparatus is intended for use in maintaining a given range oftemperature in a compartment or an apartment where thermostatic means islocated for controlling the apparatus. The temperature of thecompartment or apartment is affected, on the one hand, by changes inheat generated by the. 3}.)Pt1ltltll3, and, on the other hand, bychanges in the atmospheric temperature.

Briefly the apparatus consists of a boiler, an atomizing burner operatedby steam from ti 0 boiler and supplying heat to the boiler as well as tothe compartment or apartment 30 that is to be heated, either directly orindirectly), means for controlling the proportion of heat applied to theboiler, as, for example, a damper movably supported between the burnerand the boiler, and means operated by steam pressure for actuating theformer means or damper. It is to a unique form of this steam pressureoperated means that my present invention has particular reference.

In the present embodin'ient of the inven- 0 tion, this pressure operatedmeans consists of a plurality of bellows arranged] to be thrown into andout of communication with the boiler respectively as the atmospherictemperature rises and falls, so as to vary the steam pressure requiredto deflect the heat from the boiler, as by moving the damper towardboiler shielding position. in inverse ratio to the number of bellows incommunication with the boiler.

Obviously, as the atmospheric temperature drops. a greater head of steamis required to operate the burner so as to feed more fuel and produce ahotter fire and thus bring the temperature of the compartment or apart-55 went up to the required degree. To accomplish this the controln'iechanism functions to reduce the numbiir ofbellows that are incommunication with the boiler and to permit a greater proportion of heatto be applied to the boiler. As the atmosspheric temperature rises, alesser head of steam is requiredto operate the burner and the controlmechanism acts to increase the number of bellows that are incommunication with the boiler and thus permit a lesser proportion ofheat to be applied to the boiler.

In the accompanying drawings, Fig. 1 is a front elevation, and Fig. 2 aright hand side elevation of my improved fuel oil burning apparatus;Fig. 3 is a sectional left hand elevation, and Fig.1. 4 a sectional planview of the apparatus; Fig. 5 is a transverse vertical sectionsubstantially on the line 55 of F ig. 3; Figs. 6 and 7 are sectionaldetails of the auxiliary burner control valves; Fig. 8 is a frontelevation of a plurality of bellows for controlling the damper; Fig. 9is a side View, partly in section, of the valve for controlling thepassage of steam to and its exhaustfrom the bellows that are shown indetail in Fig. 8, and of the electrical mechanism through which saidvalve is operated; Figs. 10 to 13 are sectional details on therespective, correspondingly numbered, lines of Fig. 9, the valve beingshown in the same position in all views; Fig. 14: is a vertical sectionthrough the electrical mechanism for controlling the aforesaid Valve;Fig. 15 is a section on the line 15 15 of Fig. 14; Figs. 16 and 17 areelevational views, at right angles to each other, of one of the pawlcarrying plates of said electrical mechanism; Figs. 18 and 19 are,respectively, a side elevation and a plan view of one of. the pawls ofsaid mechanism; Fig. 20 is a wiring diagram of the electric controlcircuitinvolving the aforesaid mechanism, a thermostatic switch, and aswitch operated intermittently by a moving part of the apparatus; andFig. 21 is a sectional detail of one of the burners.

The apparatus comprises box like casing 1, having a removable top 2, andwithin the lower portion of the casing is located a re fractory walledcombustion chamber 3 hav ing an opening 4 in its roof through which theproducts are adapted to pass into a compartment 5. Housed within therear portion of this compartment is a boiler 6 that is adapted toreceive a part of the products of combustion, when the damper 7 islifted, the

damper being fulcruined at its forward edge on the corresponding sidemember of a frame 8 that surrounds the opening l.

The rear wallof the casing 1 has an opening 10 which is adapted toregister with an opening 11 in the front wall 12 of a furnacedesigi'iated generally by the reference numeral 15. This furnace may beof any approved type, as, for example, house heating furnace of thesteam, hot water, or hot air vari ety. In adapting a furnace of ordinaryconstruction for use'with my fuel oil burning apparatus, the grate ispreferably removed and the opening it) of the apparatus is placed inregister with the ash pit door so that, as a matter of fact, the firebonof the furnace into which the combustion chamber of the apparatusdischarges is composed of the space which ordinarily comprises the lirepot and ash pit.

Projected through an opening 19 in the front wall of the casing l is aburner designated generally by the reference numeral 20,

the same comprising a main section 21 and auxiliary sections 22. Fueloil is supplied to the burner through a conduit 23 and its branches 24:from a reservoir 25 that is situated, in the present instance,on theright hand side of the apparatus, and the same is kept supplied withoil, to the level of an overflow pipe 26 that rises from the bottom ofthe reservoir, by means of an oil pump 27 which receives oil from asuitable source through a pipe 28 and delivers it through a pipe 29 tothe reservoir; The overflow pipe 26 discharges into a pipe 30 thatpreferably leads to the source of supply with which the former pipe 28communicates. The oil pump 27 of the reciprocating type and is operatedby a steam motor 33. This motor is preferably of the cylinder and pistonvariety and a plunger 34, carried by the piston (not shown) projectsthrough the rear wall of the casing. Following the usual construction ofmotors of this kind, the valve mechanism involving a rod 35, is actuatedby the plunger through the intervention of a link 36 that is fulcruinedatone end to a stud 37 on the motor casing and is pivotally connected atits opposite end to the plunger 34 and intermediate its ends to the rod35. A contact plate 40 is carried by the plunger 34 and is adapted, uponeach reciprocation of the plunger, to make contact with a stationaryplate 4L1 that suitably carried by an adjacent part of the structure.'The purpose of these contact plates will presently be described.

A steam dome 44 is connected through a nipple 45 with the top portion ofthewboilcr 6, and steam is conducted from said dome, through pipes 47and 48, and through a tube 49, to the main section 21 of the burner 20.Steam is also conducted, through branch 50 of the pipe e7, to the steammotor Supported on the right hand side of the casing 1 are the valves,illustrated in detail in Figs. 6 and through which the passage of steamto the auxiliary burner sections is controlled. The structure involvingthe valves is tlesis 'natcd generally by the reference numeral c1 and itcomprises a base 52 having an inlet port 523 and two outlet ports 5 theL 1,1 H. j T 21 Kl s4- lattei ports being COl1UL()lAK l lj valves soUlla are carried by frusto-conical members 56 that L :i do one of theend walls of the ,.lows i)! whose'onnosite ends are swaoed withinopenings or a plate so. iiie edge or this oiaic is CiiilllPQCl betweenthe peripheral i the base and a liar portion of .we 59 of a frame 60,the parts being secured together by 0:13 screws 61. lit will be seenfrom this construction that the space between the plate 58 and the base52 and into which the inlet port opens communicates with the interior ofthe bellows 57. Adjusting screws 63 are threadct through the frame (30in substantially axial alignment with the valves 55, and springs arecompressed between spring s 65 that are applied to said adjusting screwsand the portions the frusto-conical i'neinbei's 56 which carry thevalves 55. iii shell 67 encloses the frame 60 and bellows 57 and is heldin place by a cap screw 68 that extends through an opening in the shelland threaded into a boss 69 of the frame 60. Tubes TO lead from theoutlet ports to the auxiliary sections f the burner 20, whilecommunication is established between the steam dome ieof the boiler land the inlet port through a branch 72 of the steam pipe 4118.

It is apparent from the foregoing con struction that the steam pressureof the boiler is at all times communicated to the interior of thebellows 57. (i/hen th steam pressure exceeds the pressure of the springs64:, the bellows are expanded and lift the valves off their seats so asto throw the auxiliary burner sections into communication with the steamsupply. In order to cause one of the auxiliary burner sections to comeinto operation after the other, as w n the steam pres sure has reachedgiven value one of the springs ea is adjusted to a higher t nsion thanthe other, the left hand spring in Fig. 6 be ing shown as compressedsomewhat more than theright hand spring Tater is supplied to the boiler6 through an inlet pipe 75, and its admission is controlled by suitablevalve mechanism that is actuated by a float 76 hou d within a floatchamber 77 which constitutes an emension of the boiler, the float,through its connection with the valve mechanism, serving to maintain asubstantially constant water level in the corresponding end of thedamper 7. A rod 84 constitutes the forward end of the lever 82 and thesame projects through an openino 85 in the front wall of the casing. Aweight 86 is applied to the rod 84 and is adapted to be held in anyposition to which it is adjusted along the rod, by a set screw 87. Theweight 86 is set to overhalance the damper 7 and hold it in openposition. This action is counteracted by the steam operated mechanism towhich my invention has special reference and which I shall now proceeedto describe.

Depending from the horizontal branch of an inverted U-shaped bracket 90that is located in the upper, forward portion of the casing 1, are aplurality of bellows, desig nated respectively, A, B, C, D and E. Interposed between the lower ends of the bellows and the bottom walls ofsockets that are formed in a cross member of the lever 82, are thrustpins 96. Through "connections which I shall presently describe,communication is established between the boiler 6 and the bellows sothat upon an accumulation of sufficient steam pressure within certain ofthe bellows, the rear portion of the lever 82 will be depressed againstthe action of the weight 86 thereby to lower the damper 7 to closedposition.

Suitably supported adjacent the right hanc side of the apparatus is avalve which is designated generally by the reference numeral 98, thevalve casing being designated 99 and the valve body 100 (see Figs. 9 to13). The valve body is secured, as by pins 101, to a shaft 102 that issupported by and between the end walls of the casing, the upper one ofsaid end walls being removable and held to the casing by screws 103.This end wall has a stulling gland 104 to prevent leakage where theshaft extends into the valve casing. lVhere the shaft protrudes abovethe casing it has se cure-d to it a worm wheel 106 which is adapted tobe drivenby aworm 107 on a shaft 108. The shaft 108 is rotatablysupported within the front wall of a casing 109. Secured to the innerend of the shaft 108, within said casing. is a spur gear 110. the teethof which are adapted to be engaged by the noses 111 of pawls 112 thatare pivoted at 113 to pawl carrying plates 114. These plates are nor--mally maintained in the position shown in 14 by the engagement of screws115, that are threaded for adjustment through lugs 116 of the pawlcarrying plates, with the side walls of the casing 109. Pivotallyconnected at 117 to portions of the pawls 112, that are offset withtheir pivots 113. are links 118 which have their upper ends pivoted tothe lower ends of the movable core sections 120 of solenoids 121 and122. housed within the enlarged upper end of the casing 109 and coveredby a plate 122.

Returning now to the valve 98, steam is ad- -out disturbing theirrelative at mitted to the upper end of the casing 99 thereof through apipe 125 which connects adjacent the steam dome 44 to the previouslymentioned pipe 47. It will be observed from Fig. 9 that the pipe 125enters the valve ing 99 above the valve body 100, and at a pointsubstantially diametrically c jiposiie the steam inlet pipe, a pipe aleads to the bellows A. Consequently, the bellows A always incommunication with the boiler. Through pipes i), c, (if and c, the valvehas connection with the respective bellows B, C, D and E. The passage ofsteam through the pipes Z), 0, (Z and e, is controlled by the valve body100. Formed along one side of the valve body is a plurality of supplyports, I), c, d and e. Opposite the supply ports 6 and cl are exhaustports (Z and c and the side wall of the valve body is cut away upwardlyof the aforesaid port (I to provide a passageway 50 through which thepipes 7) and 0 may communicate with the exhaust port (Z? when the valvebody is in certain positions. Steam and condensate are ex hausted fromthe lower end of the valve casing 99 through a pipe 128.

Figs. 10 to 13 inclusive represent transverse sections through the valvein the plane of the respective ports 7), c, d and. c. It will beobserved that said ports terminate at one end in a line parallel. iththe axis of the valve body, while at their other ends they progressspirally about the valve body. The same is true of the exhaust ports, aswell as of the passageway as, and the parts of the valve body whichseparate the supply and exhaust ports are of suificicut width to prevent simultaneous communication of any one of the pipes Z) to c with asupply and. haust port.

Located within the compartment or apartment that is to be heated by theapparatus is a thermostat shown in connection with the diagram of F 20.This thermostat is comprised of a base 131 on which is mounted athermostatic element 132 the free end of which is adapted to swingbetween and en gage contacts 133 and 134 that are adjustably carried bya plate 135 that pivoted at 138 to the base. By swinging this plate thecontacts 133 and 134 may be aoji :ted with. re spect to the thermostaticel ent withstment. 135 is for the anism cause The adjustment of theplate purpose of changing the me it to maintain different tcd ratemperature, while the adjustment 0 tacts 133 and 134 is to increase ordecrea .e range. To facilitate the setting of the plate 135 for giventemperature ra es, it pro- 'vided with a pointer 13'? which cooperateswith a scale 138 on the 131.

A source of electric energy is represented in Fig. 20 by a battery 140.One side of the battery is connected through a conductor 141 llO tactpoint rmostatic element 135. The conwith the tht 1s connected through acon- Y tor 146.

The construction of one of the burner sections illustrat ,d in 21. 1t.comprises frame 150 which incorporates tubular bosses 151 and 152 towhich the oil and steam pipe" are connected, respectively, by suitableunions 153. The frame incorporates sleeves 154iand 155 into which an oilnozzle S and a steam nozzle 15'? are adapted. to be inserted from thefront of the frame. Each nozzle has a comparatively small duct whichopens into a port that is adapted to register with the correspondingtubular boss 152. Adapted to be drawn toward the frame 150 by a bolt 160is a head 161 which bears at its opposite ends on the forward ends ofthe nozzles 156 and 157. The belt 160 extends through the frame and atits inner-end receives a clamping nut 162. l orwardly of the frame, asecond clamping nut 163 is carried by the bolt.

i-lrranged trai'isversely of the lower porti on of the casing 1 belowthe passageway 1 in the roof of the combustion chamber is a preheatingburner 165. This preheating burner is in the nature of a pan having aplurality of dues 166 rising from a horizontal wall 167 below whichthere is an air passageway 168 that supplies air through the ducts .of'the lines 166 to support combustion. A quantity of suitable oil may beintroduced into the burner pan through a filling spout 169 that is nor,.ally closed by a cover lit), said cover also serving to close anopening 171 through which the preheating burner may be lighted.

i'ltssum ug that water is present in the boiler to the level permittedby the valve mechanism controlled by the float 76, and that a supply ofoil is in the reservoir 25, to set the apparatus in operation, thepreheating burner is filled and lighted and the flame therefrom riseshrough the passageway at and is deflected 'carwardly by the damper 7about the boiler 6, :he products passing on through the openin 11 intothe fire pot of the furnace, it ben under stood that in the absence of agiven W ssure in the boiler the damper is held in el rated position bythe weight 86. As soon as steam is created in the boiler it passesthrough the oipes 17 and 4:8 and through the tube 49 to the middlesection 21 of the burner and starts said section of the burner inoporation. This main burner then supplies heat pre within the casing 99by the control mechanism involving the thermosta 130 and the solenoids121 and 122. It will be ned,for the purpose of description, t lat thebellows l3 and C, as well as bellows A, are in communication with theboiler. As soon as sufficient steam pressure is created in the boiler toact through these three bellows to depress the damper against the actionof the weight 86, the damper will be moved to closed position and shieldthe boiler from the products of combustion, all of the products theissuing through the rearend of t 1e combus "i sham or 3 into the firebox of the furnace. Upon a consequential drop in the steampressure, thedamper will again rise to permit a part of the products to have accessto the boiler, nd under an unchanging temperature condition, the damperwill finally assume and'maintain a medial position. 7

Let it now be supposed that the atn'iospheric temperature has dropped tosuch an extent that the temperature of the compartment or apartment inwhich the thermostat 130 is situated is lowered enough to cause thethermostatic element 132 to swing to the right into engag ment withcontact 133 whereiiipon a circuit is established, each time the steammotor 33 operates to bring the contact plates 10 and 4:1 in o engagementwith each other, from the battery 140, through co tic 1411, tlermostatic element 132, contactv 133, conductor 142, solenoid 121,conductor 1 1 1, and, through the ground, the motor casing 33, contactmembers and ll, and conductor 1&5, back to the battery. This will resultin the solenoid 121 being energized intermittently, and as its movablecore section. is retracted it will, through the link 118, first swingthe corresponding pawl 112 to project its nose 111 into engagement withone of the teeth of the spur gear 110, and further movement of the coresection will cause the pawl carrying plate 1141 to swing about the axiso. shaft 108 and rotate the gear and consequently the shaft through themedium of the pawl, each impulse of current passing through the solenoidcausing the shaft to be rotated a lin'iited dist nee. The rotation ofthe shaft 108, and consequent ly the worm 107 that is secured to theshaft forwardly of the casing 109, causes the valve body 160 to berotated through the worm gear 106 and shaft 102. The direction ofotation of the valve body is such as will cause first the bellows C andthen the bellows B (provided the temperature condition on which thisaction is predicated exists for a suificient length of time) to be cutoii from the steam supply and exhausted through the passagmvay 00 andport (Z to the exhaust pipe 128. acting through the lever 82 to depressthe damper 7, to the one designated A, and consequently a much higherhead of steam will be required to closethe damper than was the case whenthe three bellows were in communication with the boiler. This increasedsteam pressure naturally creates a hotter fire because the volume ofsteam being increased causes a great quantity of oil to be injected withthe steam into the combustion chamber. WVhen the steam pressure reachescertain predeter-,

mined values, the valves are opened through the expansion of theircontrolling bellows 57 and steam is admitted to the auxiliary burnersections 22, thereby to further increase the fire.

While I have described the extreme case in which all bellows (exceptingbellows A that is always in communication with the boiler) are'cut offfrom the steam supply and both auxiliary burners are thrown intooperation,

it is obviousthat as soon as the temperature oi the compartment orapartment rises sufliciently to cause the thermostatic element 132 towithdraw from the contact 133, theoperation of the control mechanismwill cease and the apparatus willremain in its newly adjusted.

position until a further temperature change occurs that will cause thethermostatic elethrough the branch of the circuit including the solenoid122, whereupon said solenoid will I be energized intermittently and,through the mechanism above described, rotate the valve body in theopposite direction and throw into communication, through the ports I), 0etc., the corresponding bellows; and as the number otbellowsthat arethrown into communicationwith the boiler increases, a lower steampressure will prevail inthe boiler because of the fact that with theincreased capacity of the bellows the damper 7'will be moved towardclosed. position under the lesser head of steam. This results in areduction in the size of the flame, the auxiliary burners becominginactive as soon as the steam pressure recedes beyond theaforesaidpredetermined values.

V Having thus described my invention, what I claim is 1- 1. a Incombination, an atomizing burner, a

boiler situated to receive heat from the burner and from which boilerthe burner receives its steam supply, means for supplying oil to theburner, means controlling the proportion of This reduces the number ofbellows,

means communicating with the boiler for actuating the controlling means,and temperature controlled means functioning independently of the steampressure in the boiler for varying the quantity of steam delivered tosaid steam operated means.

2.. In. combination, an atomizing burner, a boiler situated to receiveheat from the burner and-from which boiler the burner receives its steamsupply, means for supplying 5 burner, a boiler situated to receive heatfrom the burner and from which boiler the burner receives its steamsupply, means for supplying oil to the burner, means controlling theproportion 01": heat applied to the boiler, steam operated meanscommunicating with the boiler tor actuating the controlling means, meansfunctioning independently of the steam pressure in the boiler forvarying the quantity of steam delivered to said steam operated means,and thermostatic mechanism subjected. to the temperature in thecompartment for controlling said quantity varying means.

4. In oil burning apparatus for heating a compartment, in combination,an atomizing burner, a boiler situated to receive heat from the burnerand from which boiler the burner receives its steam supply, means forsupplying oil to the burner, a member arranged to intercept the passageof heat from the burner to the boiler and movable between a positionwherein it does, and a position wherein it does not, shield the boilerfrom the heat of the burner, said member tending to move ber to theother position, conduits for delivering steam from the boiler to therespective devices, valvemeehanism functioning independently of thesteam pressure in the boiler for controlling-the passage of steamto thedevices, and; thermostatic mechanism subjected to the temperature in thecompartment for controlling said valve mechanism.

5. In oil burning apparatus for heating a compartment, in combination,an atomizing burner, a boiler situated to receive heat from the burnerand from which boiler the burner receives its steam supply, means forsupplying oil to the burner, amember arranged to intercept the passageof heat from the burner to theboiler and movable between a positionwherein it does, and a position wherein it does not, shield the boilerfrom the heat of the burner, said member tending to move toward one ofsaid positions, a plurality of steam operated devices for moving saidmember to the other position, conduits for delivering steam from theboiler to the respective devices, valve mechanism for controlling thepassage of steam to the devices, and thermostatic mechanism subjected tothe temperature in the compartment for actuating the valve one directionwhile the energization of the other solenoid causes the valve to bemoved inv the opposite direction, an electric circuit including a sourceof energy and two branches, each branch involving the winding of one ofthe aforesaid solenoids, a thermostatic switch in said circuit by meansor" which one or the other of the branches is electrically connectedwith the source of energy, a second switch in thecircuit, and means forintermittently closing said second switch.

7. In con'ibination, an atomizing burner, a boiler situated to receiveheat from the burner and from which boiler the burner receives its steamsupply, means for supplying oil to the burner, a member arranged tointercept the passage of heat from the burner to the boiler, sald memberbeing movable from a position wherein it shields the boiler from theheat of the burner to'a second position wherein 1t is ineliective, themember tending to move toward'one of said positions, a plurality ofsteam operated devices for moving the member toward the other position,conduits through which steam is delivered from the boiler to saiddevices, and valve mechanism controlling the passage of steam throughsaid conduits, the valve mechanism serving, when moved in one direction,to throw said devices successively into communication with the boilerand, when moved in the opposite direction, to similarly cut oli thesteam supply to said devices and exhaust them.

8. In combination, an atomizing burner, a boiler situated to receiveheat from the burner and from which boiler the burner receives its steamsupply, means for supplying oil to the burner, a member arranged tointercept the passage of heat from the burner to the boiler, said memberbeingvmovable between a position wherein it shields the boiler from heatof the burner and a second position wherein it is ineffective, themember tending" to move toward one of said positions, a plurality ofsteam operated devices for moving the member toward the other position,conduits through which steam is delivered from the'boiler to saiddevices, valve mechanism controlling the passage of steam through saidconduits, the valve mechanism serving, when moved in one direction, tothrow said devices successively into communication with the boiler andwhen moved in the opposite direction to similarly cut oil? the steamsupply to said devices and exhaust them, mechanism for actuating saidvalve involving two solenoids, one of which when energized moves thevalve in one direction, the other when energized serving to move thevalve in the opposits direction, an electric circuitincluding a sourceof energy and two branches, each branch involving the winding of one ofsaid solenoids, a thermostatic switch for elec trically connecting oneor theother of saidbranches with the source of energy, a second switchin said circuit, and means for in termittently closing said secondswitch.

9. In combination, a plurality of atomizing burners, a boiler situatedto receive heat from saidburners, conduits leading from the boiler tosaid burners, valvesincertaln of said conduits, steam operated devicesconnected to said valves and serving to open them when the steampressure within the boiler attains predetermined values, means forsupplying oil tothe burners, means controlling the proportion of heatapplied to the boiler, steam operated means communicating with theboiler for actuating the controlling means, and temperature controlledmeans functioning independently ofthe steam pressure in the boiler forvarying the quantity of steam delivered to the last mentioned steamoperated means.

10. In oil burning apparatus for heating a compartment, in combination,a plurality of atomizing-burners, .a. boiler situated to receive heatfrom said burners, conduits 'leading from the boiler to said burners,valvesin certain of said conduits, steam operated devices connected tosaid valves and serving to open them when the steam pressure within theboiler attains predetermined values,

means for supplying oil to the burners, means controlling the proportionof heat applied to the boiler, steam operated means communieating withthe boiler for actuating the controlling means, and thermostaticmeansvsubjected to the temperature in the compartment for varying thequantity-of steam delivered to the-last mentioned steam operated means,

11. In combination, a plurality of atomizing burners, a boiler situatedto receive heat from saidburners, conduits leading from the boiler tosaid burners, valves in certainof said.-

. have communication with the boiler for ac-V conduits, steam operateddevices connected to said valves and serving to open them when the steampressure within the boiler attains predetermined values, means forsupplying oil to the burners, means controlling the proportion of heatapplied to the boiler a plurality of steam operated devices adapted totuating the controlling means, and temperature controlled meansfunctioning independently of the steam pressure in the boiler forthrowing certain of said devices into and out of communication with theboiler.

12. In oil burning apparatus for heating a compartment, the combinationof an atomizing burner, a boiler situated to receive heat from theburner and from which boiler the burner receives its steam supply, meansfor supplying oil to the burner, means for controllin the proportion ofheat applied to the boi er a plurality of steam operated de' vicesadapted to have communication with the boiler for actuating thecontrolling means, means for throwing certain of said devices into andout of communication with the boiler, and thermostatic mechanismsubjected to the temperature in the compartment for controlling the lastmentioned means.

In testimony whereof, I hereunto aflix my signature.

LEE S. CHADWICK.

